Change-over switch



Jan. 11, 1944, R. K. SHEWMON 4 .CHAPIGEHQVER SWITCH Filed Jan. 21, 1942 INVENTOR Page K .Sfizwman BY 4 y 6: 4-way, M! M HIS ATTORNEYS Patented Jan. 11, 1944 I CHANGE-OVER SWITCH Ralph K. Shewmon, Dayton, Ohio, assignor to General. Motors Corporation, Detroit, Mich., a

corporation of Delaware Application January 21, 1942, Serial No. 427,613

11 Claims.

This invention relates to electric switches, such as change-over switches for changing circuit connection for electric motor or other electrical devices.

An object of the present invention is the provision of an improved construction and arrangement in switches of the type disclosed having relatively few parts which are easily assembled and which may be manufactured at low cost.

Another object is to provide a novel form and assembly arrangement of the stationary and movable contact elements of the switch.

Another object is to provide novel mounting means for the switch mechanism as a whole. By this invention a single switch construction is provided which can be used to control two different circuits.

Another object of the present invention is to provide a switch that an unskilled operator can manipulate from one circuit closed position to another and that in either position it may be locked in said position so that it can not be acciclentally moved to another position not proper for the particular voltage of the current supplied to the device.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a top view of a support and. switch assembly embodying the principle of the present invention and,

Fig. 2 is a bottom view of the same.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.

Figs. 4 and 5 are views taken substantially along lines of 4-4 and 5--5 of Fig. 3.

Fig, 6 is a perspective view showing the elements of the switch in separated relation.

Referring to the drawing 20 designates a cupshaped housing of non-conducting material having a partition 2| to divide the interior of housing into two compartments 22 and 23. The side walls of the,housing are provided with notches 2m to receive bolts by means of which the housing is fastened in place to the desired support. The closed end 24 of the compartment 23 is provided with an opening 25. Disposed within the 001m partment 23 is a rotor or actuating member 26, which is preferably made of a non-conducting material. This actuating member comprises a body 27 having at one end thereof an integral boss 28 which projects outwardly through the opening 25. The end of the boss is tapered and knurled so that it may be readily grasped to turn the rotor. The other end of the rotor is provided with a boss 29 having a projection 33. The rotor has a passage 3! therethrough. The passage is of step formation to provide a non-round section 32 to form a shoulder 33, and an enlarged circular portion 34 within the confines of the boss 28. The circular portion 34 is enlarged at its end to provide a shoulder 35.

The non-rounded portion 32 of the passage receives a metal insert 35 tapped at each end. The contour of the insert is complementary with the contour of the non-round section 32 and has a close fit therewith. It is to be understood that the insert may be embedded within the body if preferred. The boss 28 has a transverse opening 31, Fig. 1, therethrough to receive an indicating bar 38. This bar is provided with an opening through which passes a threaded stud 39 having threaded engagement with the insert 36 for maintaining the insert within the non-rounded portion of the passage recess 32 and also for holding the carrier 21 in assembled relation with the support 20 as hereinafter described.

The body 21 of the carrier 283 has a plurality of spaced cavities or recesses 40 which are adapted to house loosely springs 4| to urge yieldingly bridging metal balls or rollers 42 against partially spherical contact surfaces 43 disposed on the inner face of a base 44. The springs M are so formed that in spite of the clearance between the ball and the walls of the recess the springs will not slip around the sides of the balls and thereby become wedged therebetween. The spherical contact surfaces are mounted on shanks which extend through the base and riveted over on the bottom face of the base and adapted to be connected to wires of an electric circuit.

The base 44 is provided with a bearing opening 45 and an arcuate slot 46. The opening 45 receives the projection 30 while the slot 46 receives a lug 41 extending from the boss 29. The opposite ends of this slot 46 limit the rotational movements of the rotor 26 by acting as stops against which the lug 4! abuts. The side edges of the base 44 are of such formation that they will have a close fit between the partition 2| and the opposite wall of the compartment 23 so as to prevent the base from turning within the compartment. The central areas of the base 44 abut the flat surface of the boss 2%. The base is held within the compartment by a headed stud 48. The head abuts the bottom face of the base 44 while the shank thereof has screw threaded engagement with the insert 3& Fig. 3. The base carries rods 53 the free ends of which engage the inner face of the wall of the compartment. These rods prevent the base from rocking on the rotor and assists in maintaining the base in parallel relation with the wall 2%.

According to the invention two adjacent spherical contacts 33 are bridged by one of the balls 42 to close an electric circuit. The spacing of the contacts provides a space between adjacent contacts and the size of the balls are such that when the balls are between two stationary contacts the ball will yieldin ly engag simultaneously two contacts so as to close the electric circuit. By providing loosely mounted ball contacts the possibility of the contacts binding is substantially eliminated. They also make the switch operate more easily when the switch moves from one position to another. Further due to the inaccuracy that may happen in the manufacture of the switch parts the contacts may not be spaced in the proper relation in each instance when the switch parts are assembled together. Thus, by mounting the balls loosely in their respective recesses there is enough clearance between each ball and the walls of the recess in which it is mounted to allow the ball to center itself between two stationary contacts having partially spherical contact surfaces. For example, when the actuator is moved from one position to another the axis of the recess may not be exactly between two stationary contacts consequently the ball will be out slightly. Due to the fact that each ball is loosely mounted in the recess it will move in the direction necessary to center itself between the two stationary contacts, and thereby compensate for any irregularities of switch manufacture.

It is a feature of the invention to indicate whether the 119 or the 220 volt supply circuit is connected. It is to be understood that this switch can be used for any other possible change, for example, speed changes and reversing changes. In the present instance the wall 24 or the compartment 23 is provided with openings and 5| and the fiat surface of the rotor abutting the inner flat surface of the Wall 2 is provided with notations, for example 220 and 110 imprinted therein. Other notations can be used, depending upon the particular use for which the switch is intended. The rotor is also provided with tapped holes spaced from the notation. One of the tapped holes and one of the notations will be uncovered in each position of the switch; the particular notations uncovered depends upon the angular position of the actuator with respect to the housing. When the proper notation is exposed by one of the openings the rotor is locked in position by a screw 53 having screw threaded engagement with tapped holes exposed by the other opening.

It is to be understood that the wire or cables 55 which are attached to the riveted over ends of the shanks of the stationary contacts are so connected that certain cables are connected with the contacts adapted for the carrying of heavy current and the other cables are connected with contacts of less current carrying capacity. Thus, when the actuator is moved to the position shown in Fig. l, the notation 220 is uncovered by the opening 50 the balls 12 will bridge certain stationary contacts to complete circuits appropriate for operating current consuming device from a 22.0 volt supply circuit; and that when the actuator is in the position in which th opening 5| will uncover the notation 110, the proper connections are made for operating current consum ing devices from a volt supply circuit.

In order to change the position of the actuator from one position to another, it is merely necessary to unscrew the screw 53 from the tapped hole to allow the actuator to be rotated the angular distance the arcuate slot 35 will allow the lug 41 to be moved after which the screw is threaded into the tapped hole in alignment with the opening 56 so as to lock the body in position to prevent accidental movement of the actuator.

The recess 34 is closed by a washer which is press fitted in the circular portion at and rests on the shoulder The washer prevents tampering with the screw and also adds to the outward appearance of the switch.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A change-over switch comprising a support having a plurality of spaced openings; a rotor providing a plurality of movable contacts and having a boss extending through one of the openings, said rotor having two notations which are arranged to be selectively uncovered by one of the other openings; an indicating bar carried by the boss and adapted to cooperate with the outer face of the support for retaining th rotor in assembled relation with the support with one end or the other of the bar pointing at the opening revealing the uncovered notation; a base carrying stationary contacts supported from the rotor, said stationary contacts adapted to cooperate with the movable contacts, and said rotor operable to effect diiierent switching relations and to expose coincidentally on of the notations through the said one of the other openings. and removable mean for locking the rotor against rotation relative to the support.

2. A change-over switch comprising, a support, a large opening and a pair of smaller openings; a rotor providing a plurality of yieldable contacts and supporting a boss which extends through the larger opening, said rotor having two different notations which ar so arranged that only one or the other of the notations will be uncovered at a time by one of the smaller openings; a bar carried by the boss and adapted to cooperate with the outer side of the support for retaining the rotor in assembled relation with the support, said bar being so positioned that one end of the bar will point to the opening uncovering one of the notations; a base carrying stationary contacts supported from the rotor and adapted to cooperate with the yieldable contacts; provisions provided by the support cooperating with the edges of the base to prevent turning of the base; with respect to the support and removable means connected with the rotor and extending into the other smaller opening to prevent rotation of the rotor relative to the support.

3. A change-over switch comprising a cupshaped housing having its closed end provided with a plurality of spaced openings; a rotor providing a plurality of yieldable contacts and having an integral boss which extends through one of the openings, said rotor operable to difierent positions and having a plurality of notations, said notations being prearranged so that only one notation will be uncovered at a itme by one of the other openings; a bar carried by the boss cooperating with the outer face of the closed end of the housing for retaining the body of the rotor within housing with one end or the other of the bar pointing to the opening which uncovers the selected notation; a base of insulating material located within the housing; means movable with the rotor for retaining th base within the housing, the base having edges cooperating with walls of the housing to prevent rotation of the base within the housing; stationary contacts arranged in an arcuat path carried by the base and adapted to cooperate with the yieldable contacts; and removable means carried by the rotor and cooperating with one of said other openings in the closed end of the housing for locking the rotor against rotation.

4. A change-over switch comprising a cupshaped housing having parallel side walls and having an opening in itsv top wall; a rotor provided with yieldable contacts located within the housing and having a bos projecting through the opening, said boss having a transverse opening therethrough; a bar extending through the opening of the boss with the ends thereof cooperating with the outer surface of the top wall for maintaining the rotor within the housing; a base within the housing, said base having edges cooperating with the side walls of the housing to prevent the base from rotating within the housing; a plurality of terminals carried by the base adapted to be bridged by the yieldable contacts carried by the rotor; and securing means movable with the rotor for holding the base with in the housing.

5. An electric switch comprising, a cup-shaped housing having an opening in its top wall; a rotatable actuator provided with a plurality of movable contacts located within the housing and having a boss projecting through the opening, the boss having a passage therethrough and located beyond the outer face of the top wall; a bar extending through the passage, the ends of which overlie the opening to hold the rotor in assembled relation with the housing; an insulating base for the rotor, said base having edges cooperating with said walls or the housing to prevent rotation of the base relative to the rotor; stationary contacts carried by the base adapted to cooperate with movable contacts; and means supported from th rotor for holding the base in assembled relation with the rotor.

6. A switch comprising, a cup-shaped housing having substantially parallel side walls and having an opening in its top wall; a rotor within the housing having a. projection and a lug at one end and having a boss at the other end projecting through the opening, said boss having a transverse passage therethrough and located beyond the outer surface of the top wall; a bar extending through the passage with the ends thereof cooperating with the outer surface of the top wall for maintaining the rotor and housing in assembled relation; an insulating base having an apertured and an arcuate slot located with in the housing, said base having edges cooperating with walls of the housing to prevent the base from turning; a plurality of terminals projecting from the inner face of the base and having spherical contact portions circumferentially arranged on the base, the body of the rotor being provided with spaced recesses having their open ends facing the contacts; a ball loosely supported in certain of the recesses; a coil spring compressed between the ball and the bottom of the recess for biasing the ball into bridging contact with two adjacent terminals, the aperture and slot of the base receiving the projection and lug respectively of the rotor, the aperture acting as a bearing for the rotor and the ends of the slot being adapted to be engaged by the lug limiting rotational movement of the rotor; and means secured for movement with the rotor for holding the base within the housing.

7. A selective switch comprising in combination; a support having a plurality of bent portions extending therefrom; switch means comprising relatively fixed contacts and relatively movable contacts; a rotor carrying the movable contacts and provided with an extension projecting through an opening provided by the support, said extension capable of being grouped by the hand for manually rotating the rotor to effect different switching relations; means carried by the extension and cooperating with the support for holding the rotor in a certain position relative to the support; a base carrying the stationary contact with certain edges of the base cooperating with certain of the bent portion to prevent the base from turning relative to the support; means movable with th rotor for holding the base in assembled relation with the rotor; and removable means for lockin the rotor in a selected switching relation.

8. A selective switch comprising in combination; a support having an aperture; witch means including relatively fixed contacts and relatively movable contacts; a movable body carrying the movable contacts and provided with a manually operative element extending through the aperture of the support, said element being operable to effect different switching relations; means cooperating with the element and the support for maintaining the movement of the body within a certain plan relative to the support; a base carrying the stationary contacts; means associated with the support for preventing endwise and sidewise movement of th base; and means supported from and movable with the body for holding the base in assembled relation with the body.

9. In a switch of the type described the combination of supporting means having depending portions; a rotor rotatably mounted on the supporting means; removable means for holding the rotor in assembled relation with the supporting means; biased contacts movable with the rotor; a base carrying relatively fixed contacts, said fixed contacts being arranged so that each biased contact will extend between and bridge a pair of fixed contacts in each position of the rotor; removable means associated with th rotor for holding the base in assembled relation with the rotor but permitting the rotor to rotate relative to the base, said base cooperating with the depending portions to prevent rotation of the base relative to the support.

10. In an electric switch the combination comprising a support having depending elements; a base located between the elements and spaced from the support, said base carrying relatively fixed contacts and having provisions adjacent said elements and cooperating therewith so as to prevent rotative movement of the base relative to the support; a rotor between the base and support and carrying yieldable contacts adapted to extend between and bridge a pair of fixed contacts in different positions of the rotor; stub shafts carried on opposite faces of the rotor to support rotatably the rotor in aligned bearing openings provided by the base and support; removable means attached to and rotatable with a substantial distance beyond its bearing opening so as to be grasped by hand and manually operated to efiect different switching relations.

11. A switch adapted to effect different switching relations comprising in combination; a body of insulating material having a recess opening to one side thereof; a carrier located within the recess and rotatably supported on the body, said carrier having a plurality of pockets; a spring and a spherical bridging member located in certain of the pockets, said bridging members being urged outwardly by their respective springs; a base of insulating material insertable a substantial distance within recess and carrying relatively fixed contacts, said fixed contacts being arrang d so that each bridging member will yieldingly extend between and bridge a pair of fiXed contacts, there being rolling friction between the contact elements when the carrier i actuated from one switching relation to another, said body and base having provisions cooperating with each other to prevent rotation of the base Within the recess; means rotatable with the carrier for holding the base in assembled relation with the carrier and thereby hold the bridging members and springs in their respective pockets; and removable means supported by the carrier and overlying portion of the body for maintaining the carrier and the base within the recess.

RALPH K. SHEWMTON 

